Antiperspirant products typically use aluminum- and zirconium-based salts as the active antiperspirant ingredient to control perspiration and malodor. However, many consumers may hold a negative view of their use due to health and environmental concerns. Moreover, the high concentrations of the active antiperspirant ingredients can cause irreversible staining of clothing.
The above issues have been addressed in a number of ways. One approach is the addition of one or more water-soluble polymers containing Brønsted acid groups in combination with aluminium and/or zirconium salts to the antiperspirant/deodorant composition. See, e.g., U.S. Pat. No. 6,616,921; U.S. Patent Application 2005/0100521; and International Application WO 02/49590. However, in the only issued patent, the water soluble polymers are described to form true solutions in water, where a true solution typically has an absorbance of less than 0.2, preferably less than 0.1 (for a 1 cm path length at 600 nm). Also related is pending U.S. Provisional Application 61/450,303, which teaches antiperspirant/deodorant compositions having a reduced concentration of antiperspirant active while effectively controlling perspiration and malodor. The contents of the '921 patent, the '521 and '590 patent applications, and the provisional application are hereby incorporated in their entirety by reference.
A homeopathic approach eliminates aluminium- and zirconium-based salts in favor of antiperspirant actives from plant origin, such as salvia officinalis oil. While these alternative compositions have met with mixed success, they are generally regarded to be much less effective in controlling perspiration than conventional compositions. Another solution to the problem is to abandon perspiration control, and instead address malodor that can arise from the perspiration, for example, by using baking soda products. However, homeopathic responses are not adequate for many people, who must reduce or eliminate perspiration using more effective means because their preferences and/or lifestyles do not permit uncontrolled sweating, or for other reasons.
Despite the concurrent advancements in antiperspirant technology, effective antiperspirant/deodorant compositions having a significantly reduced, or even a zero level of aluminium- and/or zirconium-based salts are not known, but would be enthusiastically adopted by consumers.
Accordingly, there is a need for new antiperspirant/deodorant compositions that can reduce the high concentrations of conventional antiperspirant and deodorant ingredients while maintaining antiperspirant/deodorant efficacy.